I haven'r read the entirety of the canon yet, so I'm not sure if this has been done before, but I doubt it.
Basic idea is its a memetic disease that transfers the consciousness of the victim into all tissue shedded in the last year (ie skin cells in dust, hair, saliva). The victim is in constant pain while their brain is made from neurons of dead skin, and so tries to spread it out of spite.

So uh… I took a quick look at this, and in the interest of being completely honest, it looks like kind of a mess.

Right from the start, you have incorrect formatting—please use the template available in the How to Write an SCP Guide for the proper bolded headers, and the text following immediately after the section titles rather than on the line below. Your Item #: heading is missing, procedures is missing a colon, Task Forces generally have a nickname in quotes after the Greek-letter-number designation, and you can take out "Desquamation Event" because you only mention it once more after it's introduced. You shouldn't use any subjective extremes like "truly anomalous" (because… well, it's either anomalous or it's not, right? Wouldn't all the anomalous effects be "truly" anomalous? It's excessively flowery text for what should be a cold, clinical document). And so on.

With regards to the concept… it feels like a mess of a ton of different ideas. The description starts off with:

SCP 3010 is a disabling cogitohazard with the potential to cause an AK class End Of The World scenario. Spread is dependant on comprehending a specific phrase, involving a physiological process of shedding, a quirk of human anatomy, and the ancient Greek myth of Theseus. This phrase must be understood in order to infect an individual, hereafter known as 3010-1.

You've got a lot happening here.

"disabling cognitohazard"

end of the world scenario

comprehension of a phrase (which might be more memetic than cognitohazard, unless it's just hearing the phrase that's the trigger, not understanding it)

"physiological process of shedding"

Theseus???

None of those things really seem instinctively related, and the rest of the article just piles on extra states and terrible effects that happen to people without regards for consistency or storytelling. Furthermore, a lot of this excessively-detailed stuff seems like it's mixing author knowledge with in-universe Foundation knowledge.

Keep in mind that as the author, you know the entire story, but the Foundation needs to have discovered what it knows about the SCP object through observation and experimentation. You'll need to convince your reader that someone with no prior knowledge whatsoever of the anomaly managed to somehow figure out (not magically know!) all the information you've got in the article.

I recommend getting the base idea polished up in the Ideas and Brainstorming forum before you try fixing the draft. Go to that forum, post a quick summary of the concept you want to write up (don't link the draft unless someone asks), and reviewers there can help you with some internal consistency and less of a meandering read.

First off, thanks for taking the time to read my draft! I made the formatting changes in the first part.

This is a lot to take in to be honest and is a tad discouraging. I thought it was a decent idea. Anyway the reason I referenced Theseus was because of Theseus's Ship, a thought experiment that asks whether a ship with all its parts replaced over time is still the same ship. I thought it would be a uniquely terrifying concept if our body's mechanism of replacing cells suddenly became important to the victim's identity.

You're definitely right that the SCP is memetic, not cognitohazardous- I'll fix that, and I should probably include experiment logs that explain just how the Foundation knows all these things. I thought it was self-evident how this could cause an AK scenario, though. It is extremely contagious and would result in humanity being alive, but insane.